1. Field of the Invention
The present invention relates generally to a system and method for synchronous control of rotary printing presses, and more particularly to a system and method for synchronous control of rotary printing presses comprising a plurality of printing units, a folding unit for cutting and folding a printed paper web into predetermined printed images; drive means for independently driving the units, and control sections for controlling the drive means for the printing units being provided on each of the units; and at least one printing unit having a plurality of web paths running from the printing unit in question to the folding unit, in which the position at which the paper web is cut by the folding unit in accordance with the printed images printed by the printing unit can be automatically adjusted for each web path selected.
2. Description of the Prior Art
A newspaper press is well known as a rotary printing press having a plurality of printing units and a folding unit for cutting and folding a printed paper web into predetermined printed images. A rotary press in which printing and folding units are individually driven by independent electric motors and the control of the operation thereof are known by Japanese Published, Unexamined Patent Application No. Hei-6(1994)-47905, for example.
Disclosed in Japanese Published, Unexamined Patent Application No. Hei-6(1994)-47905 is a rotary press having individual driving sections (electric motors) for driving driven parts (cylinders) of printing units, and drive control devices for the individual driving sections as printing station groups. Several printing station groups are independent from each other and receive their respective positional references via a data bus on which the printing stations are disposed. That is, the printing station group have their respective drive units, which are connected to a data bus to which a folding unit is connected, and to the drive control devices for the printing station groups. The drive unit controls the positioning of the individual driving sections of the printing station groups in connection with the positional reference received from the folding unit, and also controls the relative positions of the individual drive sections.
An operation and data processing unit as a host master unit is connected to the data bus to which the drive unit is connected. The operation and data processing unit controls the printing station groups. That is, the operation and data processing unit presets target values and a target value difference, and processes actual value, so that the target-value control of different printing station groups can be accomplished consistently among the printing station groups and to the folding unit.
In other words, this rotary press is such that the drive control of the electric motors of the printing station groups is accomplished with respect to the positional reference received from the folding unit based on the control reference from the drive unit and the host master unit via the drive control device.
In a newspaper press, on the other hand, a bay window device BW for changing the top and bottom of a printed paper web with a combination of bay window rollers BR and BR as shown in FIG. 5, for example, with turn bars TB and TB is provided to adjust the arrangement of multi-color printing units and pages on which multiple-color images are to be printed, and a plurality of web paths for feeding the paper web on which images were printed by a printing unit CT to the folding unit FD.
In a rotary press the overall picture of which is shown by combining the right side of FIG. 3 with the left side of FIG. 4, a paper web on which images were printed by a printing unit CT1 is passed through web paths SP1 and SP5 leading to a folding unit FD bypassing a bay window device BW and web paths BP2, BP3, BP4 and BP5 from turn bars TB2, TB3, TB4 and TB5 on each stage to the folding unit FD via the bay window device BW, while each of other printing units CT2, CT3, CT4 and CT5 has web paths leading to the folding unit bypassing the bay window device BW and web paths from the turn bar TB of each stage to the folding unit FD via the bay window device BW.
In such a rotary press, where a plurality of web paths leading from a given printing unit to the folding unit have different lengths, an adjust roller device AD (refer to FIG. 5) is provided, as shown in Japanese Published Examined Patent Application No. Hei-7(1995)-17054, to allow the length of the web path to be adjusted by moving an adjust roller AR (refer to FIG. 5) of the adjust roller device AD, on which the paper web has been wound about 180 degree, to a predetermined position in parallel with the paper web at a preset value, so that any paper web that has been passed through any web path can be cut into printed images at the right position by the folding unit.
The aforementioned Japanese Published Unexamined Patent Application No. Hei-6(1994)-47905, however, discloses the construction and operation of the invention only schematically, and does not disclose any specific details of control.
As to how to control the positioning of the individual drive sections for the printing station groups, and how to control the relative positioning of the individual drive sections with each other, in connection with the positional references received from the folding unit, Japanese Published Unexamined Patent Application No. Hei-6(1994)47905 has no specific description about how to control what. Even assuming that this control is concerned with the control to properly adjust the relations among printed images and between printed images and cutting and folding, it has no specific description about how to achieve the control. It does not disclose, furthermore, that the control is concerned with a rotary press comprising printing units having a plurality of web paths, as mentioned earlier.
In a rotary press, on the other hand, an adjust roller device AD has usually been provided in front of the folding unit for each web path, as described above, to adjust so that the paper web can be cut by the folding unit at proper positions in accordance with printed images. This arrangement has involved a considerable space because the adjust roller device AD is provided for each web path, and made maintenance difficult as web paths have been increased in number and more and more complicated. Since the paper web runs through the adjust roller device AD during printing operation, unwanted tension is likely to be caused, making the travel of the paper web unstable and increasing the length of the web paths by the amount of travel via the adjust roller device AD. Thus, this arrangement has involved increased spoilage during paper web changing, at the start and end of printing. Furthermore, provision of the adjust roller devices AD has involved increased manufacturing cost.
It is an object of the present invention to provide a synchronous control system for rotary presses having a plurality of web paths in which the position at which the paper web is cut by the folding unit can be automatically adjusted in accordance with printed images for each selected web paths without using the adjust roller devices.
It is another object of the present invention to provide printing units each having at least one of a plurality of web paths leading to the folding unit, going through, or without going through bay window devices.
It is a further object of the present invention to provide printing unit control sections for receiving drive references, including drive reference speed and drive reference phase transmitted by the master control section.
It is still a further object of the present invention to provide a loop-like network line to allow a failed part of the network line to be bypassed.
It is still a further object of the present invention to provide a master control section that performs information exchange with printing unit control sections, so that the positions at which the paper web is cut by the folding unit in accordance with printed images can be automatically adjusted for each selected web path.
It is still a further object of the present invention to provide an input operation section for storing in the memory section the length value of each web path from the printing unit to the folding unit.
It is still a further object of the present invention to provide a control message and the construction thereof for designating the control range of rotary press sets organized by the processing section, and control messages and the construction thereof relating to drive references, such as drive reference speed and phase, and phase correction values for correcting the rotational phase of the printing cylinder.
It is an even further object of the present invention to provide the construction of a response message sent by the slave control section.
It is an even further object of the present invention to provide a synchronous control system for rotary presses in which even when a master control section fails, the positions at which the paper web is cut by the folding unit in accordance with printed images can be automatically adjusted for each selected web path by selectively changing over by another master control section.
It is an even further object of the present invention to provide a method for synchronous control of rotary presses having a plurality of web paths in which the positions at which the paper web is cut by the folding unit in accordance with printed images can be automatically adjusted for each selected web path without using adjust roll devices.
In disclosed embodiments, a synchronous control system for rotary presses having a master control section for controlling the entire system, drive means provided in a plurality of printing units and a folding unit that cuts and folds a printed paper web in accordance with printed images for independently driving the units, control sections for controlling the drive means of each unit; at least one printing unit having a plurality of web paths running from the printing unit to the folding unit through which the paper web is passed for printing, has such a construction that the printing unit control section having a plurality of web paths comprises a drive reference receiving section for receiving a drive reference from the master control section, a phase correction value output section for generating a phase correction value based on the length from the printing unit in question to the folding unit in a selected web path, a drive reference speed signal output section for generating a signal relating to drive reference speed based on the drive reference receiving by the drive reference receiving section, a corrected drive reference phase signal output section for generating a signal relating to the corrected drive reference phase obtained by correcting the drive reference phase based on the drive reference received by the drive reference receiving section with the aforementioned phase correction value, a feedback signal receiving section for receiving a feedback signal on the operating condition of the printing unit in question, a feedback speed signal output section for generating a signal relating to feedback speed based on the feedback signal received by the feedback signal receiving section, a feedback phase signal output section for generating a signal relating to the feedback phase based on the feedback signal received by the feedback signal receiving section, a phase difference detecting section for detecting a phase difference between the corrected drive reference phase and the feedback phase from the corrected drive reference phase signal and the feedback phase signal, a phase difference signal output section for generating a signal relating to the phase difference detected by the phase difference detecting section, and a signal correcting section for correcting the aforementioned drive reference speed signal based on the phase difference signal and the feedback speed signal relating to the phase difference between the aforementioned corrected drive reference phase and the feedback phase and generating a corrected control signal.